


A Royal Flush

by Anubis_2701



Series: SakuAtsu Fluff Week 2021 [7]
Category: Haikyuu!!
Genre: Alternate Universe - Royalty, Arranged Marriage, Childhood Friends, Enemies to Friends to Lovers, First Kiss, Growing Up, Light Angst, M/M, Medical Trauma, Mild Blood, Minor Kita Shinsuke/Miya Atsumu, Pining Sakusa Kiyoomi, Prince Miya Atsumu, Prince Sakusa Kiyoomi, Sexual Content, Temporarily Unrequited Love, Weddings
Language: English
Status: Completed
Published: 2021-02-20
Updated: 2021-02-20
Packaged: 2021-03-14 18:27:42
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,505
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29175657
Author URL: https://archiveofourown.org/users/Anubis_2701/pseuds/Anubis_2701
Summary: If someone were to ask Kiyoomi Sakusa, Prince of Itachiyama – one of the most powerful nations in all the East – who he hated most in the world, the answer would have to be none other than Prince Atsumu Miya of Inarizaki.Or, Prince Kiyoomi has been engaged to marry Prince Atsumu since he was just a child. They had despised one another since their very first meeting.Which was exactly what made falling in love with him so humiliating.
Relationships: Minor or Background Relationship(s), Miya Atsumu/Sakusa Kiyoomi, Miya Osamu & Sakusa Kiyoomi
Series: SakuAtsu Fluff Week 2021 [7]
Series URL: https://archiveofourown.org/series/2115333
Comments: 16
Kudos: 262





	A Royal Flush

**Author's Note:**

> SakuAtsu Fluff Week Day 7, Tier 1: Royal AU
> 
> Thank you to my beta [Ankal](https://archiveofourown.org/users/Ankal/pseuds/Ankal) for ironing out the creases here!!! :DDDD

If someone were to ask Kiyoomi Sakusa, Prince of Itachiyama – one of the most powerful nations in all the East – who he hated most in the world, the answer would have to be none other than Prince Atsumu Miya of Inarizaki.

They had first met at the tender age of six, and really, it had all been downhill from there.

Both their nations were powerhouses. Itachiyama churned out tempered steel so strong that it could bring any enemy  force to their knees, boasted of mountainous regions rich with natural resources, and touted endless stretches of forests that bore rich, dark timber. Inarizaki, on the other hand, was a coastal country with an impressive navy and dearth of sailors, able to drag in hauls of fish so heavy they sometimes tore through their nets.

But when Kiyoomi and Atsumu had been children, between the two nations, power had been skewed Inarizaki’s way. Itachiyama had been ravaged by a mysterious plague three years after Kiyoomi was born, and the aggressive actions of their northern neighbour, Inubushi, had them scrabbling to defend themselves and their resources. Inarizaki, bordered only by Itachiyama, with whom they’d always been fairly friendly, had no such concerns. So Kiyoomi’s mother, Itachiyama’s reigning sovereign, had sucked up her pride, crossed the border in a diplomatic mission, and pleaded for help.

And the Miya family, seeing an opportunity to tie a formidable nation like Itachiyama to their own permanently, had agreed to lend them the support of their army and navy. Under the overwhelming strength of their combined forces, Inubushi had been sent running with their tails between their legs. And, in the aftermath, as both sides had picked through their dead and tallied the loss, Inarizaki had finally asked for repayment.

The deal itself wasn’t a bad one; tying together their families was logical, and the Miyas had even been understanding enough so as to not demand that their heirs marry, sparing Kiyoomi’s eldest sister, Norie. They had accepted Kiyoomi, the second child in the family, and betrothed him to their oldest son, Atsumu, with little fanfare and less hesitation.

Just a month after it had been made official, they’d been gently nudged towards one another in the palace gardens in Itachiyama’s capital. Kiyoomi had taken one look at the deep chestnut hair of the other boy and decided he didn’t like him. Atsumu had swiftly reciprocated that opinion. Their parents had just exchanged amused smiles and left them to it, feeling assured that their feelings would change.

They’d returned an hour later to see Kiyoomi’s hair a mess from being tugged, Atsumu drenched from being shoved into a small pond, and both of them with sulky faces and arms folded, facing determinedly away from one another. More laughter had been exchanged between Kiyoomi’s father and Atsumu’s mother, respectively the parents responsible for raising them, and promises for another ‘playdate’ set up swiftly.

But despite all the attempts of their parents to endear them to one another as children, the animosity between them only seemed to grow with the passage of time through their early years. By the time Kiyoomi was eight, he’d already devolved into tears and begged to have the betrothal revoked four times. Atsumu had outdone him and sat at nine. Their parents were unyielding.

The only saving grace, at least when they were children, was that they lived in separate countries, and though their parents did their best to make them stay in touch (quite a few letters with insulting elements were exchanged, during that time), their actual in-person visits were only occasional.

* * *

At least, they were. Until Motoya had to go and open his big mouth.

Kiyoomi loved his cousin. He did. They were best friends as children, and that bond was one that would persevere their entire lives. But his cousin’s fascination with old Itachi myths was not useful when they were children.

Motoya had always loved hearing the old stories passed down from generation to generation, even if some of them had scared him  badly enough to make him crawl into Kiyoomi’s bed at night on occasion. The fables of daring adventurers, the magical creatures that used to thrive across the continent and fantastic wars enchanted him like nothing else.

But no single tale enchanted him half as much as that of the  _ Flower-Year Girl _ . It was a simple tale, believed by many to have been an old allusion to tales of archaic nature goddesses, and what helped unravel the simple peace of young Kiyoomi’s life.

The story was brief; long ago, there lived a girl who adored the warm seasons like nothing else. She would dance through rows of crops, bask in the sun and plant countless flower seeds to watch their beauty bloom. But the girl wilted like a dying rose in winter, frightening her parents with how reclusive and cold she became. The cold spread through her body like a pestilence, making her family desperate to bring the sun back into her life. So, her parents told her of a country nearby, who had summer when their own home bore winter, where she could plant flowers without risk of wilting for half the year.

And the girl listened, trekking over mountains, lakes and endless ridges when autumn began to descend on her homeland, eventually stumbling across the land her parents had spoken of. She spent six months there, passing half the year dancing and planting flowers like she had dreamt. And when the weather started to turn, she returned home, in time to join her family for spring.

Kiyoomi’s father told the story much better, always adding elaborate subplots and details that had kept them enraptured as children, but that was the basic plot he’d been taught as a child. And it had been after listening to Motoya wax poetic about the old story that a keen look had entered Kiyoomi’s mother’s eyes.

But that wasn’t even the extent of Motoya’s treachery. If he had only planted the seeds of an idea in his mother’s mind, he would have easily forgive his cousin.

But no, Motoya essentially handed the idea to her on a silver platter.

He had gone from gushing over the story to comparing it to a similar tale of a queen who spent half her year with her lord husband, the other half at her own kingdom. He adored it for how similar it was to his favourite fairytale. Until that point, Kiyoomi had enjoyed it well enough too.

Then his cousin brought up his engagement to Atsumu, and ever so innocently said, “what if Kiyo spent time in Inarizaki every year like the queen did! Like a real life story!”

The arrangement had been made not even a month later; Kiyoomi was slated to spend every spring and summer for the foreseeable future in Inarizaki, to get him accustomed to the hotter weather, culture and language before he married its future sovereign. He didn’t want to go – screaming, crying and beating his fists and generally acting up more than he ever had before in his life. It was all futile. He was packed onto a ship and shoved into Inarizaki at the start of the season, doing his best to control both residual seasickness and his sorrow when he stepped off. He had never liked boats, and despised the fact that though there was a land path between their capitals, travelling by boat was much faster. The fact that this boat was taking him to the house of someone he hated only made it worse.

His only comfort was that, as made evident by the abject horror on Atsumu’s face, he wasn’t the only one to be more than slightly displeased with the arrangement. He didn’t want to be led down the wide, open-air pavilions of Inarizaki’s palace, but Atsumu hardly wanted to lead him either.

And thus was born his newest form of entertainment; torturing Atsumu in the walls of his own home.

It was easy; Atsumu’s parents viewed Kiyoomi as a sweet but quiet boy who would undoubtedly grow into a good scholar and even better husband and advisor to their oldest son, rather than as the troublemaker that Atsumu (correctly) saw him as. So whenever Kiyoomi wanted to be shown around, or to find a certain room, he would throw a blinding smile at them and smirk as they cooed and shoved Atsumu in his direction, no doubt expecting Kiyoomi to be perfectly eager to learn and sweet as honey.

Which was what made asking Atsumu endless questions, poking him sharply between the ribs to get his attention and grabbing him by the ear if he ran too far ahead so fun.

And Kiyoomi wasn’t alone in his quest to annoy Atsumu as much as possible. Because Atsumu’s twin brother Osamu seemingly made it his life’s mission to spite Atsumu, perhaps in revenge for having been born seven minutes earlier and thus snagging the crown. He and Kiyoomi got along like a house on fire, and Atsumu screwed his nose up with horror and made it a habit to run whenever he got the chance, once they started to tease him.

He returned home to Itachiyama in the autumn with greatly buoyed spirits, conversational fluency in Inarizaki’s mother tongue, and a new friend to mail letters to.

* * *

Unfortunately, the childish teasing and poking they so keenly maintained when they were small quickly fell out of favour with everyone who wasn’t them. As their ages slid into double digits, slapping, punching and hair-pulling became things of the past, to be swiftly replaced by glaring side-eying, muttering under their breath, and other such subtle ways of expression distaste.

(Elbowing was saved for moments in private, though their parents didn’t need to know that.)

To Kiyoomi’s abject horror, now that they were teetering closer to the start of adolescence, the expectation for them to be a little more…‘lovey-dovey’ had started to pick up, and the thought of acting such with Atsumu was borderline nauseating. He complained to Osamu of the new expectations that his parents were piling on him, sending letter after letter the other boy’s way as Itachiyama slogged its way through a harsh winter.

_ He’s loud and annoying and he  _ _ hates _ _ me, _ Kiyoomi said in one letter,  _ I don’t get why we even have to get married anyway. Everyone says we have to be nice to each other now _ .

_ I know, _ Osamu replied in his next letter, obviously sharing Kiyoomi’s pain over the whole endeavour,  _ he’s a scrub, but ya gotta get married because of the alliance thing, I think. Mom won’t explain it to me properly. It's kinda funny how much you guys fight, though, especially since we get along so well _ .

That was probably the letter that inspired the idea, actually. It took several more to be passed back and forth for it to come to full fruition, but that small comment by Osamu was what started the little plot.

When Kiyoomi showed up in Inarizaki again, now 11, he was greeted by his fiancé and taken up to the palace. No-one questioned why the angry glares that normally passed between the two princes hadn’t taken place, or why the carriage ride to the palace was marked by low giggling from inside the compartment. But Kiyoomi, ensconced away with Osamu – who found impersonating his twin all too easy – was having the time of his life.

Atsumu seemed relieved by the idea, too, content to flitter around the sidelines as Kiyoomi and Osamu played the parts of a happy pair of boys destined to be future husbands and rulers. And without their time spent together suddenly being mandated, Kiyoomi found himself far less aggravated by Atsumu than usual. The other boy, it seemed, was as irritated by the enforced need to spend time together as he was.

There was no sudden blooming of friendship or even tolerance among them, but Kiyoomi could sit by Atsumu quietly (as he pretended, in his own right, to be Osamu) and not feel as strong an urge to shove him over. That summer was a much more peaceful one, though the twins knew as well as Kiyoomi that it wasn’t a farce that could be maintained long-term. For all their fighting and glaring, Kiyoomi and Atsumu knew that they were bound to marry  _ each other _ , and for as much as the situation ticked them off, they would abide by it.

* * *

Kiyoomi was 12 when he finally found out that Atsumu, constant purveyor of his own strength and prowess, who spent so much time boasting about his own skills that it grated on Kiyoomi even when his mouth was shut, was bad at some things that he himself was quite skilled at.

_ Kiyoomi _ was a better rider, able to tolerate long hours in a saddle while Atsumu moaned and complained and had to dismount every few hours to waddle around pathetically.

_ Kiyoomi _ was much better at falconry, able to churn out beautifully trained birds that both his own family and his future one cooed over emphatically.

_ Kiyoomi _ absorbed books like they helped sustain his lifeblood. Atsumu couldn’t read very well.

The last fact among the three was the most startling. For all their ribbing, the topic of books and reading had never come up much, but whenever it had (in slightly more civilised conversation) Kiyoomi hadn’t failed to notice the winces and cringing that Atsumu sometimes let slip when it came up.

Osamu danced away from the subject when he asked him, offering only excuses like, “Atsumu knows better than I do,” and “He’s the one whose reading you’re asking about, maybe ask him?”

And after a few weeks of increasing confusion, Kiyoomi did.

“Can you read?” he asked one day at lunch. The two of them had been heavily encouraged (i.e. forced) to have a picnic-like lunch outside in the gardens, which had become Kiyoomi’s favourite part of the palace not long into his first visit to Inarizaki.

Atsumu went rigid at the question, ears turning a vibrant shade of red. “Of course I can.”

“Hmm, but you can’t read  _ well _ , can you?” Kiyoomi pointed out, folding his arms when Atsumu hunched his shoulders in and scowled. “That’s what I thought.”

“Shut up!” Atsumu snapped, turning away with a huff, “The words just don’ turn out right! They…s-spin and stuff! It’s not my fault!”

Kiyoomi watched him impassively, a little surprised to see legitimate distress in Atsumu’s eyes. For as long as he had known his future husband, Atsumu had only expressed emotions like smugness, anger or petulance. Seeing this…rubbed him the wrong way, somehow. He averted his eyes, plucking a few blades of grass from the ground and scattered them so that the wind caught them and sent them flying away.

“Well, I don’t want to be married to an idiot, so I guess I’ll teach you to read better.” He mumbled. Atsumu looked at him, face still screwed up with anger. Kiyoomi refused to look at him, plucking out more grass.

“Fine,” Atsumu huffed, “I’ll let ya, if only so I can prove that ya ain’ as smart as ya think ya are.”

Kiyoomi narrowed his eyes, acknowledging the challenge and accepting it wholeheartedly. “Deal.”

They started the next day, Kiyoomi dragging Atsumu to the library and sitting him down, pulling up a stack of books and forcing him to concentrate. It  _ was _ something of a labour, especially with how Atsumu seemed to mix up and miswrite characters, but by the time Kiyoomi was packing his things to return home, Atsumu had churned his way through half of a book that Kiyoomi had read and seemed eager to get his hands on more.

“I can send you a letter with some good books listed,” Kiyoomi said as servants stacked his things back onto the boat, fiddling with his hands as he and Atsumu spoke. He had never sent Atsumu a letter before; the six months each year he spent at home, he had already gotten updates on Atsumu from his twin. For some reason, the prospect made his stomach feel a little weird.

Atsumu brightened up. “Oohh, okay! I’ll be way better a reader when ya get back! Better than ya, even!”

Kiyoomi’s eye twitched. “No, no you won’t. I’ll read more books than you.”

“Bring it!”

“Fine!”

“Atsumu! Stop shouting and say goodbye to Prince Kiyoomi!” Atsumu’s mother called from the other side of the boat. Atsumu wilted a little at being chided, but grabbed Kiyoomi’s hand in a firm handshake, dragging him closer and leaning forwards to whisper in his ear.

“I’m gonna beat ya.” He smirked as he pulled away, not giving Kiyoomi a chance to reply before he jumped down to the docks, sending a lackadaisical wave before sprinting back over to where his parents were disembarking. Kiyoomi just stared after him, slowly returned the wave, and absently wondered why his chest felt so warm.

* * *

When Kiyoomi turned 13, he had his first kiss. And had anyone told him who he’d have his first kiss with, back when he had been a child hung up on romance stories like his cousin, he would have called them a bold-faced liar. Yet he found himself on the night of Yuletide, the biggest winter festival in Itachiyama, to which royals from all over the continent had been invited, pressing his lips against those of none other than Miya Atsumu, eternal annoyance and provocateur extraordinaire.

He hadn’t been expecting it; the other prince had practically ambushed him where he had been lingering in the hall and just smashed their lips together. The circumstances themselves didn’t precipitate some amazing show of passion. And that was a good thing; his first kiss wasn’t too magical.

It was…extremely awkward.

Their movements were clumsy, Atsumu had almost headbutted him when he’d first lurched forwards, and the whole feeling was a lot wetter than he had expected. It was, first and foremost, weird and strange, and the feeling of their teeth clacking together when they separated made Kiyoomi wince slightly, but…

(He didn’t hate it?)

_ He didn’t hate it _ .

Atsumu turned a deep shade of red as he pulled away. “There! Done!”

Kiyoomi stared at him. “What?”

“Mom told me I should do all the Yuletide traditions with ya, and ya were standin’ under the holly! Don’t go making fun of me! Ya were just as bad!”

Kiyoomi pressed a hand tentatively to his mouth, brain still lagging behind the conversation by about two whole minutes. “Uhhh-”

“Whatever,” Atsumu huffed, turning on his heel and marching off, “go find Samu if ya wanna have another kiss, because I ain’t giving you one!”

And as the usually petulant prince rounded the corner and vanished, all that Kiyoomi could reasonably think was,  _ why would he think I wanna kiss Osamu? _

He returned to the Yuletide party with his stomach fluttering nervously, and the slowly burgeoning realisation that he, at least, didn’t hate his betrothed as much as he used to.

Kiyoomi didn’t tell anyone that, of course; he would die than perhaps admit that maybe, just maybe, his mother had been right all those times she had insisted that love was capable of blooming between him and Atsumu. He  _ didn’t _ love Atsumu; he was barely even sure he  _ liked _ him. The only thing he knew for sure was that he kind of liked sending and receiving letters from Atsumu, and that kissing him felt kind of nice inside. That was it.

He maintained that view for the entire rest of the night, watching married couples dance together and kiss while keeping up the usual annoyance he felt at the thought that one day he and Atsumu would be expected to do the same.

Until he watched Atsumu get coaxed onto the dance floor by some Inari noble’s daughter, saw her specifically direct them over to a spot underneath a bough of holly, and had to sit by and observe as Atsumu, who had kissed him less than three hours ago, kissed her too.

He went to bed early, citing a sore stomach, and found himself curled up under his covers, regrettably aware that  _ maybe _ , just  _ maybe _ , the fact he was upset over Atsumu kissing someone else constituted feelings of ‘like’.

* * *

If Kiyoomi had been certain of one thing the entire time he and Atsumu had known one another, it was that they both viewed their situation with the same level of disgust. They didn’t want to be betrothed, definitely didn’t want to be married, and that sentiment was the only thing that had connected them over the years.

Which was why, when he imposed a cold shoulder on Atsumu upon returning to Itachiyama, limiting their formerly weekly correspondence to a single letter a month, he felt more than a little deceptive for doing such. He was certain the other boy would have come up with his own reasons for it; Kiyoomi being moody, or perhaps just them remembering how strong the flames of hatred used to be, between them and acting accordingly.

He didn’t care what explanation Atsumu invented for his sudden coldness, only that he didn’t come close to considering the real reason as an option.

Because Kiyoomi was, in his mother’s words,  _ wounded _ .

It was a statement he contested frequently – he wasn’t upset, wasn’t betrayed or feeling strangely forlorn over the prospect of Atsumu kissing that noble’s daughter – he just remembered how annoying his fiancé was, and decided to go back to avoiding him like he had when they were younger – it had worked a treat when he was 8, so why wouldn’t it work now?

His mother just tutted, his sisters rolled their eyes, and Kiyoomi continued to sulk around for the entirety of winter. He was reluctant to go back to Inarizaki, but he was nothing if not an obedient son and diligent prince, so he caught the usual boat back, mumbled his ways through greetings and fielded the Inari king and queen’s comments on how much taller he had gotten, before slinking off to his room to be alone.

“Yer bein’ weird,” were Atsumu’s first words to him that year. “Why’d ya stop sending as many letters?”

Kiyoomi huffed slightly, setting down a neatly folded stack of clothes with a little more force than necessary. “I remembered how annoying you are,” he said smoothly, tone sharp, “which is extremely so.”

Atsumu screwed up his face. “And yer back as a jerk, okay,” he snapped, “seems about right.” 

He stormed out of his room, leaving Kiyoomi in slightly regretful silence. It was for the best, he figured to himself. Fighting with Atsumu would probably stop his weird, warm feelings about the other boy from getting any worse.

It didn’t work.

Being around Atsumu constantly only reminded him why he had started to maybe like him a little. The fact that Atsumu was doing constant swordplay training and thereby filling out a little definitely didn’t help, and Kiyoomi found himself retreating to the library more than once to avoid staring at the other.

Even being around Osamu more didn’t help, because all that Kiyoomi’s young, hormonal brain could think about was the twins in contrast. Which obviously, inevitably led back to thoughts of Atsumu.

The worst part was that Atsumu seemed completely oblivious to  _ everything _ ; not just Kiyoomi’s feelings, which he wanted to be secret, but also why kissing that noble girl had upset him so much, the fact that his stranglehold on how many letters he sent  _ wasn’t actually _ because he found Atsumu annoying, or that he was trying to avoid him.

For all his efforts to stay away, Atsumu gravitated toward him almost inexplicably, perhaps desiring to rekindle the more antagonistic relationship that they’d once had. Kiyoomi didn’t know how to tell him how hurtful it was. He just dismissed it, let them settle back into their usual impassive relationship, and let Atsumu remain oblivious to his feelings.

(Because time apart and time together had proven what Kiyoomi had feared; he  _ liked _ Atsumu.)

His obliviousness was obvious, because for all his faults, Miya Atsumu was not cruel. He made jabs and taunts and gave sinister glares, but he was never unnecessarily mean or sadistic by any means.

Which was how Kiyoomi knew the other felt nothing for him, and had no idea of Kiyoomi’s feelings, the day that Atsumu plopped into the grass beside him and Osamu, and immediately started to moon over the new gardener’s son.

His name was Kita Shinsuke, Atsumu explained with a slightly bashful grin. And he was, apparently,  _ incredible _ .

Kiyoomi was going to be married to Atsumu when he was 20, and the continued health of the bond between their nations was dependent on that marriage, so rather than turn down his mouth, kick at Atsumu’s shins and run off, he stiffened up, averted his eyes and listened as Atsumu rambled along. He curled his hands into fists when Atsumu focused on Kita’s ‘pretty eyes’ and clenched his jaw when Atsumu broke from his reverie and asked Osamu if he should try asking the boy out.

“I’m going to the library,” Kiyoomi muttered, getting up abruptly and marching off. He heard a low slap right as he was leaving earshot, and a squawked question from Atsumu. He winced. So, Osamu had evidently picked up on his feelings. He should have figured.

_ I don’t care what he does _ .  _ If he wants to date a gardener’s son, he can. _

He told himself that over and over every time he saw Atsumu walking with the boy in question, laughing or talking. He repeated it under his breath when Osamu threw vicious glares at his oblivious brother across the table, before dragging Kiyoomi off to do something fun in town.

He mumbled it into palms made slightly watery by tears after he saw them kiss one day in the gardens, formerly Kiyoomi’s favourite place in the whole palace.

“My brother’s a dumbass,” Osamu told him the day he was set to leave, as he helped him pack the last of his things. “Just ignore it and he’ll eventually come to his senses. Ya’ll write to us both, right? He complains when ya write me and not him, the fuckin’ moron.”

Kiyoomi just chuckled softly, closing the last of his suitcases. “Yeah, I’ll write to you both, promise.”

Osamu grinned, patting him on the shoulder. “See ya next year.”

“Yeah, see you.”

* * *

He didn’t see them next year. In fact, he didn’t go to Inarizaki at all. Or for the two years immediately following that.

Itachiyama had borders to the north with two nations. One, Kamomedai, who was always peaceful, happy to trade furs and coal for timber and steel. Their relations had always been good. The other, however, was Inubushi. A nation that they had warred with once already within his lifetime, a nation that sneered at making deals even when its people were clamouring for more resources. A nation that had been eying Itachiyama’s border with greed ever since they’d first been rebuffed during Kiyoomi’s early childhood.

Kiyoomi wasn’t surprised that war broke out. Border scuffles between Itachi and Bushian people had been happening since the last war, and the southern trajectory of soldiers over the last few months had been an obvious and horrifying sign. He  _ was _ surprised, however, that his family chose to keep him close.

“Inubushi has a navy, too, and I would rather not send you to a whole other kingdom when we have a war here. I want to know what is happening to you,” his mother had run a hand through his hair as she said it, “I’m sorry, Kiyoomi, but I want our family to be close right now.”

He could understand her reasoning, and it was with a heavy heart that he sent letters to both Osamu and Atsumu explaining why he wouldn’t be seeing them until the war had ceased. Osamu’s return letter was calm and concise, wishing Itachiyama luck until their Inari reinforcements got there, and expressing a desire to see Kiyoomi again once everything was over.

Atsumu had no such restraint. The letter he received from his fiancé was more extensive than most field reports on the battle that Kiyoomi had watched his mother parse through, laying out so many things in so much detail that he honestly struggled at times to make sense of it all. He did his best to respond to them both, and stay calm in the face of mounting bad news about Inubushi.

Kiyoomi’s older sister spent most of her time locked away in war meetings, hearing updates on the conflict, while Kiyoomi and the rest of the palace paced nervously about waiting for news. Sick of being useless, he had gone to visit the palace doctor, and asked if there was any way he could learn first aid, to help the injured soldiers pouring into the capital.

The man had been all too happy to teach him, and despite his parents’ reservations, he was turned loose four months later to help administer emergency care alongside a trained field medic named Iizuna.

They took to each other as a fish did to water, and though he could understand Atsumu’s fascination with Kita Shinsuke a little better after spending time with Iizuna, his brain wouldn’t allow him to feel anything more than respect and fondness for the 18-year-old. Atsumu had burrowed too deep, it seemed.

Days once filled with reading, court politics and study became dominated by suturing injuries, applying tourniquets to severed limbs, and having countless people stop and stare when they realised that a member of the royal family was among them, handling blood and gore every minute. He had more than one curious soul ask if he was  _ really _ the prince, which greatly increased Iizuna’s tendency to refer to him as ‘your majesty’ just to watch them squirm in shock.

He didn’t mind the work, though, as long as the days could get. It felt good to make an active change, rather than stay ensconced behind palace walls. As he had argued to his mother when she had begun to fear how exposed it made him, it was better for him to help his people directly than benefit from their sacrifice without making one of his own.

(Making her cave had never been an easy task, but for once, he found himself successful, and the amount of time he spent helping the injured with Iizuna increased drastically.)

But regardless of how good it felt to offer a helping hand, most people had anticipated the war would be a brief one, Kiyoomi included.

Which was why it was such a blow to hear from his parents that he wouldn’t be going to Inarizaki the year he turned 16, either. His birthday was a quiet affair, overshadowed by the sight of bloodied soldiers being dragged into medical tents in the capital that they’d witnessed earlier. Its only saving grace was the letters he got from the twins. Atsumu had sent another verifiable essay and box of Inari teas his way, and Osamu had sent the very welcome news that Atsumu and Kita Shinsuke’s brief fling hadn’t gone anywhere.

_ He said that Kita didn’t challenge him enough _ , Osamu’s letter – practically saturated with a smug kind of knowingness – explained,  _ so I think he’s slowly coming to his senses _ .

As welcome a piece of news as that was, Kiyoomi had no time to dwell on it. Inubushi’s forces had been pushing more and more viciously into Itachiyama’s territory, and even with the help of Inarizaki, they were still being overwhelmed in countless areas. More injured men and women came through the capital gates by the day, and Kiyoomi quickly found himself run off his feet, pulling 14-hour shifts alongside other healers and medics.

And the battle kept raging on. What was expected to be perhaps six months of conflict stretched past the three-year mark with ease, and it was only as the months leading up to Kiyoomi’s 18 th birthday were waning that the tide definitively turned, and permanently. Just six weeks before, under Itachi law, Kiyoomi would become an adult, Itachiyama slammed its boot down on Inubushi’s back, and kept it there.

There was little fanfare; thousands dead and countless more injured wasn’t a cause for celebration, in his mother’s words, but there was a sense of calm. A feeling that they could all breathe out, now.

So, on the night he turned 18, Kiyoomi sat outside on the stairs of the palace among the medics he’d spent the better part of three years becoming close with, and drank to a future still uncertain.

* * *

One benefit of the war finally ending that Kiyoomi had anticipated but been oddly hesitant to organise was that he would be allowed to return to Inarizaki. He made his plans with eagerness and trepidation in equal measure, cautious about doing too much too fast after his long absence. Kiyoomi hadn’t been to the country, once so painstakingly familiar, in four years, and he could only imagine the changes that it had undergone since, to say nothing of the people he would reunite with there.

Kiyoomi knew he had changed, very notably where his appearance was concerned. He was a lot taller now, towering over the rest of his family with ease, and most townspeople as well. He’d cut back his curls to make his medical work easier, so it was less an untamed mess and more of a tasteful side-sweep of neatly trimmed hair. His whole body had become leaner and lither, toned from hours of hauling heavy stretchers and pallets full of medical supplies for the last few years. He’d gotten a lot of sun, too, so the natural underlying olive sheen of his skin was finally on proper display.

Being so tall and tanned now, he honestly looked more Inari than Itachi now, a fact not lost on his mother.

“Only two years left,” she’d said wistfully, tracing his hairline with a gentle hand, “then you go to them permanently. I don’t know where all those years went.”

But it wasn’t just Kiyoomi’s appearance that had changed. Years of being a first-line responder had changed his personality too. He was slower to anger, much harder to shock, offend or aggravate, to say nothing of the compassion that caring for others had awoken within him.

He was almost grateful that wild seas meant his ship got delayed by hours and hours, and only slid into the ports at Inarizaki’s capital so early in the morning that the streets were deserted, sky not still dark but not yet light with the first rays of sun. He was happy to disembark with his things and make his way quietly up to the capital.

Inarizaki’s king and queen had stayed up to greet him. Queen Ibara actually teared up when he dropped into a respectful bow.

“None of that,” she said, tugging him into a hug, “you know you’re family, here.”

He felt too buzzed to sleep, a fact he relayed to the king and queen after they were done marvelling over how tall he’d gotten and how ‘strikingly handsome’ he apparently was now. Smiling in understanding, they ushered themselves to bed, bidding him to ask for food from kitchen staff whenever he desired it, and leaving him to re-explore the secondary stage of his childhood.

Not much had changed, he reflected as he silently looked through long hallways, the gardens he had always adored so much, and eyed massive banquet rooms. There were some new draperies, a few rooms where furniture had been rearranged, and a new rose garden near the king’s quarters, since he’d apparently acquired a strong love of them recently. But other than that…it was still Inarizaki. Still Kiyoomi’s home away from home.

Atsumu and Osamu had been lured into going on a short hunt with the Inari War General, the king explained over breakfast after Kiyoomi had managed to snag a few short hours of rest. He was a little disappointed that they weren’t around already, but his mood was quickly buoyed again upon hearing that apparently, the king and queen had seen no necessity to inform them of his arrival.

“So…they have no idea I’m here,” he surmised. The queen smiled.

“None at all. Do with that information whatever you wish.”

‘Whatever he wished’ ended up being scaring the living daylights out of both twins after they’d returned, exhausted, from their hunt. The pair, identical as ever (save a change to their hair that knocked a bit of air out of Kiyoomi’s lungs) had stumbled into the hall to speak with a servant when he had seen fit to announce his presence.

Atsumu was blond now, he observed, ignoring how the sight of his long standing fiancé stirred warmth in his chest, even now. He had enjoyed some other company over the few interim years, mostly in the form of a few sleep-deprived or alcohol-fuelled makeout sessions with Iizuna, but never had he devoted any true romantic feelings to anyone else.

Seeing Atsumu now, it wasn’t hard to remember why. His fiancé had only gotten more beautiful with time, though, as he reflected with delight, he appeared to be slightly shorter than Kiyoomi now.

Kiyoomi had been sitting by a low table, near the corner of the kitchen area, watching the two obliviously speak with a chef to see if they could procure a late lunch. He watched them, marvelling over Atsumu and finding amusement in how the twins still poked at one another, before speaking up.

“You know, getting here earlier would mean you wouldn’t have to go through all of this.”

Osamu had turned first, face contorting into confusion before recognition set in, he laughed, and jogged over as Kiyoomi had let a rare smile appear, and stood.  _ “Shit _ , hey Kiyoomi. Been a while.”

“To say the least,” he drawled before glancing over Osamu’s head to look at Atsumu. “Hey.”

“…Hey,” Atsumu said, sounding a little breathless still from climbing all the outside stairs. “Uhh, g-good to see ya. Ya got taller.”

Kiyoomi blinked impassively. “You got blonder.”

“Oh, uh, yup.”

Osamu laughed softly, slapping Kiyoomi on the back before moving the other direction through the kitchen. “Have fun, kiddos.”

“I’m older than ya, jackass,” Atsumu grumbled, eyes never leaving Kiyoomi’s face. “I never even heard ya were comin’.”

“Yeah, it sounds like your parents planned it that way,” he said, smiling slightly to himself as he recalled the conversation, “did I miss anything interesting?”

Atsumu just stared at him a moment longer, apparently more caught off guard by his sudden appearance than he’d thought, before he shook his head slightly, as if jolting himself back to reality. “Oh, uh, no. From the sounds of it, yer the one who’ll have all the interestin’ stories.”

Kiyoomi shrugged. “I suppose so. I do have a few, if you really want to hear them.”

Atsumu did, and they passed hours like that, seated together in the kitchens, snacking on the food provided by the chefs as he laid out the last four years of his life.

It was nice. Too nice.

Nice enough to remind Kiyoomi’s already fluttering heart that  _ yes, _ he’d had feelings for Atsumu for many years now, and he still had then now.

The revelation didn’t hurt as much as it once did.

* * *

This visit to Inarizaki was different. Not just for how hard he had to work to make up for the years of separation between him and the Miya family, but also because Atsumu  _ kept looking at him _ . Kiyoomi was used to stealing long glances at the other man, but he wasn’t at all used to making eye contact when he stole said glances.

He didn’t understand what had changed; he and Atsumu’s letters had remained pretty much the same over the four years of war, so why did he now feel so knocked off-kilter in the other’s presence? He’d learnt to manage his feelings for the other boy well, so the constant barrage of warmth he felt from every accidental brush of their arms against one another was baffling.

And perhaps it was increased maturity, but Atsumu seemed so much more  _ tender _ than he’d been before. He brought Kiyoomi tea when he spent too many hours locked away in the library, brushed his curls off his forehead whenever his hair got unruly, had even gone so far as to grab him by the hand to lead him somewhere.

It was a slightly jarring change from their last in-person meeting, but the whole thing felt so light and natural that Kiyoomi just let himself get swept up in the gentle tide, carried along by the easy affection blooming between them.

It wasn’t all easy; Atsumu attracted a lot of attention, both due to his status as crown prince and as an incredibly attractive young man, but Kiyoomi was mildly astonished to see exactly how much of the attention was rebuffed.

As in,  _ all of it _ was rebuffed.

Where Atsumu had before at least entertained flirtations, he now gently turned them down to keep discussing a book he’d read with Kiyoomi. He had ceased smirking and winking at pretty servants in favour of tugging on the hem of whatever Kiyoomi had chosen to wear that day and commenting on the make and fabric. He turned his blinding smiles on Kiyoomi rather than on visiting nobles, and caught  _ him _ by the elbow as they passed one another in the hallways rather than any pretty potential lovers.

“I told ya he would come to his senses eventually,” Osamu explained briefly one day, leaving Kiyoomi a red-faced mess in the middle of the hallway. “I think he figured it out when we were about 17. Enjoy the idiot’s undivided attention, I guess.”

Things came to a head during that year’s summer solstice festivities. They were always an elaborate affair, and Kiyoomi wouldn’t hesitate to say he had missed the celebrations in his time away. He was dressed in a shade of deep gold, an outfit highlighted with small touches of deep, emerald green. A cloak in a light shade of amber – the Miya family’s insignia colour – was draped over his shoulders, a circlet made of gold settled against his temples.

He didn’t realise the significance of all the touches of colour until he had made his way down to the hall and saw that Atsumu was dressed essentially in the inverse; dark green with small accents of gold and a cloak that matched his own. It…tugged very hard on his heartstrings, to see them matching. Judging by how warm and genuine Osamu’s smile was when he made his way over to them, he agreed.

“Stop gawkin’ at each other and start drinkin’,” he demanded, shoving cups of spiced wine at them both, “this  _ is _ a festival.”

They obeyed, the air between them still feeling strangely static as they mingled among the other guests. But Kiyoomi could hardly focus on anything that people were saying to him, his eyes drifted back to Atsumu with such high frequency.

In line with the rest of his visit that year, Atsumu met his gaze every single time, eye contact getting distinctly heavier as the night bled on.

When Kiyoomi set down the cup of water he’d been drinking the last hour, excused himself from the party and went upstairs, Atsumu followed him.

Kissing him again dragged the air from his lungs; the feel of their connected lips was far more fluid and practiced than it had been the first time under the holly all those years ago. Having Atsumu’s lips move from his mouth to his neck was new, the sensation making him gasp and keen under sturdy, strong hands.

It felt like a dream when the cloak bearing the Miya family insignia was gently tugged off his shoulders, along with everything else he had been wearing. More so when Atsumu dragged his hands in intoxicating patterns up and down Kiyoomi’s chest, fingers dwelling on the softer skin of his inner thighs.

Most surreal of all was having Atsumu lean over him, pressing a gentle kiss to his mouth at the same time that he pushed himself inside. Kiyoomi could only shudder at the closeness, dig his nails into Atsumu’s back and pull him closer still, legs forming a prison he didn’t think the blond wanted to escape.

Every movement brought them closer and separated them once more, and Kiyoomi came undone with Atsumu pressed so close against and inside him that he could barely keep track of where he ended and the other began. They cleaned themselves up with few words exchanged, tumbling down to sleep with their arms wrapped around one another, and Kiyoomi’s head tucked beneath Atsumu’s chin.

Kiyoomi never wanted to look away from Miya Atsumu again.

* * *

Despite everything, they changed little.

Kiyoomi still did his utmost to rile up the blond, still prodded at him and shared friendly jabs and laughed whenever the other did something stupid. But they also kissed fervently, shared a bed many more nights after the festival, and pressed themselves close to each other at every opportunity.

Neither of them said the words, not even as Kiyoomi’s slated time in Inarizaki once more came to an end, and he boarded a boat to return home. Atsumu just gave him a soft smile, leant up on the boarding ramp to kiss him goodbye, and saw him off. Osamu had a field day rolling his eyes over that.

They still exchanged letters like usual, with the only difference being that useless formalities were abandoned in favour of flirtatious comments, some so suggestive on Atsumu’s part that Kiyoomi stopped opening his mail at breakfast, to the immense amusement of his family.

He leant the local medical centre his hands again while he had nothing better to do, happy to reunite with Iizuna but careful to keep a professional distance, this time. The other man seemed to understand, thankfully, and exchanged light chatter with him about what Inarizaki was like.

“I guess it feels a little strange to me, to hear about an arranged marriage,” the man said, “us commoners never really take part in them. But they’re quite typical for you royals, huh?”

“Seems so.”

“…As long as you aren’t unhappy with the idea, I suppose.”

Kiyoomi shrugged. “I mean, I’ve known since I was six, so I’ve had plenty of time to adjust to the news anyway, but even if that wasn’t the case, I……I do love him, so it’s not much of a chore to marry him.”

Iizuna just smiled, all calm acceptance and happiness. “Good. And thank you for what you’re doing for the Itachi-Inari alliance, too.”

“…My pleasure.”

Getting back to Inarizaki after he turned 19 was more of a thrill than usual. Not just because this time, Atsumu launched himself at him in a hug, or pressed a kiss to his mouth immediately after greeting him, or even because he got introduced to an impassive looking green-eyed man who was apparently Osamu’s paramour of sorts. No, it was mostly because, as the gleam in Atsumu’s parents eyed suggested, with just a year remaining until they finally made good on their engagement, it was a good enough time to start planning the wedding.

The Miyas were  _ relentless _ , and Kiyoomi found himself being tugged alongside a dreary Atsumu to look over countless options for just about every conceivable cog in a wedding machine. He didn’t know if the napkin colour mattered  _ that _ much, but Atsumu’s parents sure seemed to think so, so he went along willingly enough.

It was exhausting, though, to the point that the king and queen set them free from the preparations perhaps halfway through the summer, after gaining permission to essentially organise the event as they wanted it.

“Are ya sure we didn’t make a mistake in lettin’ my parents organise the whole thing?” Atsumu panted one day after thoroughly making love to him, rolling off Kiyoomi’s chest to wipe them both down before sitting up with a debonair grin. “I mean, they’ll make it a lot more fancy than it has to be.”

Kiyoomi shrugged and rolled onto his side, tracing a finger down the bare skin of Atsumu’s thigh. “I don’t mind, honestly. We’ve been building up to it for so long they might as well have their fun.”

“I’d rather do somethin’ simple, ya know?” Atsumu snuggled down next to him and ran a hand through his curls. “Wouldn’t it all be easier if we could jus’ say our vows then go fuck?”

Kiyoomi snorted. “Pervert.”

“Where yer concerned? Always.”

Kiyoomi hummed, reaching out a hand to gently trace along Atsumu’s side. “Tsumu.”

“Mm?”

“…I love you.” The confession was a long time coming, and they both knew it. The words still made Atsumu stiffen up and gasp, face crumpling into a teary smile before he wrapped Kiyoomi tightly in his arms and pitched them both backwards.

“And I love ya. So much.” Atsumu murmured into his hair, pressing feather-light kisses to the crown of his head. “Fuck.”

Kiyoomi settled more comfortably back against him, appreciating the warmth of their bodies being slotted together. “What are you thinking?”

“I’m thinkin’ that I can’t wait to marry ya.”

* * *

If someone were to ask Kiyoomi Sakusa, Prince of Itachiyama, who he hated most in the world, the answer would have to be none other than Prince Atsumu Miya of Inarizaki.

But, standing atop the summer pavilion in Inarizaki’s palace, hands loosely interlaced with Atsumu’s as their marriage rites were read out – his heart thundering eagerly as his parents beamed at him from the audience – if someone were to ask him who he  _ loved _ most in the world, the answer would have to be none other than Atsumu, too.

The silver and white outfit he’d been put in was a little restrictive around his ribs, and the collar was itching at his jawline, but the small irritations were inconsequential to the feel of Atsumu’s familiar hands holding his own. The blond smiled at him, eyes slightly watery with happiness as finally, blessedly, the officiant came to the end of the rites.

“Do you, Atsumu, accept Sakusa Kiyoomi as your husband and hereby induct him into your noble house?”

“Yes,” Atsumu said, grinning as he squeezed Kiyoomi’s hands. The warmth in his chest was reaching an apex, spreading to make his whole body tingle in anticipation. “Always.”

“And do you, Kiyoomi, accept Miya Atsumu as your husband, and accept your transition into his household?”

“Yes,” Kiyoomi said, returning the comforting squeeze and internally shedding the surname he’d borne all his life. “Always.”

“Then I hereby pronounce you lawfully married before the saints,” the officiant said, stepping back with a smile. “Congratulations.”

And when Atsumu leant forwards to kiss him, the motion cast against a backdrop of cheers and applause by all in attendance, Kiyoomi knew he was home.

**Author's Note:**

> Come say hello to me on [Twitter](https://twitter.com/2701Anubis), [Tumblr](https://anubis2701.tumblr.com/), or, if you're a fan of my fics generally (both BNHA and Haikyuu) my [Discord Server!](https://discord.gg/VeAaGy3at9)


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